68 mustang w/4.6dohc, engine starts and cuts right off

[jcautoresto]

Hello everyone. I have a 68 mustang with a ford racing 4.6dohc engine and procharger. I've been trying to find the problem for about 3 weeks now. I finally got everything hooked up and loaded my tune in. Tune is just to drive it around and break in the engine. The car starts right up and then shuts down. Sometimes immediately and sometimes it stays running for about 5 seconds. The strange thing is if I push the gas pedal down just a quarter of the way it will just turn over but not start. I've been working with the company that did my tune as well but so far no luck. I've checked for vacuum leaks and will check the timing later today. Wiring is ron francis and the computer is 04 cobra. Pats anti-theft has been turned off. Checked wiring into ron francis computer and everything looks good. I still don't know if it is the computer, tune, wiring, etc. I need to figure out why it will not start with the gas pedal slightly push down. That might lead to the the problem. When it does start you can push the gas pedal to try to rev it up but it's unresponsive. I attached the list I gave to the tuning company as well. Any ideas would be great. Thanks.

92170 92169

Engine:
-04 ford racing cobra block from MMR performance
-bored/honed to 4.75, compression is 9.0:1 compression
-60lb fuel injectors
-accufab wide mouth throttle body
-sullivan upper and lower intake
-3/4” sullivan fuel rails
-SCT big air mass air flow, model# BA3000 on a 3” pipe
-D1 procharger, procharger racing blow off valve
-stock 03/04 DOHC cobra heads
-stock 30/04 cobra coils
-return style fuel system with aeromotive fuel pressure regulator, 6an fuel lines
-K&N air filer
-Headers with front NTK oxygen sensors, no catalytic converters
-knock sensors
-Internals:
-4340 forged 4.75 crankshaft
-forged steel 5.933 mmr I-beam rods w/arp rod bolts
-forged Manley pistons
-clevite rod and main bearings
-ford racing oil pump
-MMR performance water pump
Transmission/drivetrain:
-digital speedometer
-tko 600 transmission
-spec stage 3 clutch
-3.70 gears
-9 inch rear with 31 spline axles
-aluminum drive shaft
Misc.:
-hydroboost brake system
-airbag delete, ant-lock brake delete, traction control delete, cruise control delete
-vintage air a/c with 98 cobra air compressor
-Remove all emissions rear oxygen sensors, air pump, canister purge, egr, fuel tank pressure
sensor
-Remove Pats anti-theft system
*Ron Francis wiring with telorveck computer system that plugs into 04 cobra computer
*SCT tuner 3000 XP0816110AE00
*Computer YDH0

[Mach Par]

I'm saying it's with the tune. Either the PATS isn't fully turned off or something within the tune. I know it's not the same car but my 04 GTO had it's anti-theft program kick in every time I loaded a new tune and it was really annoying.

[jcautoresto]

I think it is in the tune as well. When my mechanic hooked up the computer to it he found a couple things that should of been removed from the computer. I'm going to have another company do a tune as well and see what happens.

[Josh@Ridetech]

I'm definitely going to say the tune is the culprit as well.

[Derek@ModernSpeed]

While I agree with the others, it's most likely a parameter in the tune, go back, and check the reference voltage at your sensors. Your tps should have 5V going in, and somewhere near 1V coming out. The throttle should have a response of some sort regardless of what the tune is. I hope this isn't a BAMA Tune.

[jcautoresto]

No its not a bama tune. It is an emailed tune though. Thanks for that info I'll check it out tonight. Not sure what happened but I do have a throttle response now when I push the pedal down on start up. I was given two tunes so I need to see the difference in throttle response because I did switch the tunes a couple of times. It will rev up now but cut off right after. When I turn the car it does run for a couple seconds (not great though) but when you push the throttle down it dies. It will also cut off by itself eventually as well. I'm now working with Pro-Dyno and see what happens. I'll probably have to trailer it there.